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// Licensed under the MIT license. See LICENSE file in the project root for full license information.

//JZlib 0.0.* were released under the GNU LGPL license.Later, we have switched
//over to a BSD-style license. 

//------------------------------------------------------------------------------
//Copyright (c) 2000-2011 ymnk, JCraft, Inc.All rights reserved.

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//modification, are permitted provided that the following conditions are met:

//  1. Redistributions of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.

//  2. Redistributions in binary form must reproduce the above copyright
//     notice, this list of conditions and the following disclaimer in 
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//  3. The names of the authors may not be used to endorse or promote products
//     derived from this software without specific prior written permission.

//THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
//INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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//
// ReSharper disable ArrangeThisQualifier
// ReSharper disable InconsistentNaming
namespace DotNetty.Codecs.Compression
{
    /// <summary>
    /// https://github.com/ymnk/jzlib/blob/master/src/main/java/com/jcraft/jzlib/StaticTree.java
    /// </summary>
    sealed class StaticTree
    {
        const int MAX_BITS = 15;

        const int BL_CODES = 19;
        const int D_CODES = 30;
        const int LITERALS = 256;
        const int LENGTH_CODES = 29;
        const int L_CODES = LITERALS + 1 + LENGTH_CODES;

        // Bit length codes must not exceed MAX_BL_BITS bits
        const int MAX_BL_BITS = 7;

        internal static readonly short[] static_ltree =
        {
            12, 8, 140, 8, 76, 8, 204, 8, 44, 8,
            172, 8, 108, 8, 236, 8, 28, 8, 156, 8,
            92, 8, 220, 8, 60, 8, 188, 8, 124, 8,
            252, 8, 2, 8, 130, 8, 66, 8, 194, 8,
            34, 8, 162, 8, 98, 8, 226, 8, 18, 8,
            146, 8, 82, 8, 210, 8, 50, 8, 178, 8,
            114, 8, 242, 8, 10, 8, 138, 8, 74, 8,
            202, 8, 42, 8, 170, 8, 106, 8, 234, 8,
            26, 8, 154, 8, 90, 8, 218, 8, 58, 8,
            186, 8, 122, 8, 250, 8, 6, 8, 134, 8,
            70, 8, 198, 8, 38, 8, 166, 8, 102, 8,
            230, 8, 22, 8, 150, 8, 86, 8, 214, 8,
            54, 8, 182, 8, 118, 8, 246, 8, 14, 8,
            142, 8, 78, 8, 206, 8, 46, 8, 174, 8,
            110, 8, 238, 8, 30, 8, 158, 8, 94, 8,
            222, 8, 62, 8, 190, 8, 126, 8, 254, 8,
            1, 8, 129, 8, 65, 8, 193, 8, 33, 8,
            161, 8, 97, 8, 225, 8, 17, 8, 145, 8,
            81, 8, 209, 8, 49, 8, 177, 8, 113, 8,
            241, 8, 9, 8, 137, 8, 73, 8, 201, 8,
            41, 8, 169, 8, 105, 8, 233, 8, 25, 8,
            153, 8, 89, 8, 217, 8, 57, 8, 185, 8,
            121, 8, 249, 8, 5, 8, 133, 8, 69, 8,
            197, 8, 37, 8, 165, 8, 101, 8, 229, 8,
            21, 8, 149, 8, 85, 8, 213, 8, 53, 8,
            181, 8, 117, 8, 245, 8, 13, 8, 141, 8,
            77, 8, 205, 8, 45, 8, 173, 8, 109, 8,
            237, 8, 29, 8, 157, 8, 93, 8, 221, 8,
            61, 8, 189, 8, 125, 8, 253, 8, 19, 9,
            275, 9, 147, 9, 403, 9, 83, 9, 339, 9,
            211, 9, 467, 9, 51, 9, 307, 9, 179, 9,
            435, 9, 115, 9, 371, 9, 243, 9, 499, 9,
            11, 9, 267, 9, 139, 9, 395, 9, 75, 9,
            331, 9, 203, 9, 459, 9, 43, 9, 299, 9,
            171, 9, 427, 9, 107, 9, 363, 9, 235, 9,
            491, 9, 27, 9, 283, 9, 155, 9, 411, 9,
            91, 9, 347, 9, 219, 9, 475, 9, 59, 9,
            315, 9, 187, 9, 443, 9, 123, 9, 379, 9,
            251, 9, 507, 9, 7, 9, 263, 9, 135, 9,
            391, 9, 71, 9, 327, 9, 199, 9, 455, 9,
            39, 9, 295, 9, 167, 9, 423, 9, 103, 9,
            359, 9, 231, 9, 487, 9, 23, 9, 279, 9,
            151, 9, 407, 9, 87, 9, 343, 9, 215, 9,
            471, 9, 55, 9, 311, 9, 183, 9, 439, 9,
            119, 9, 375, 9, 247, 9, 503, 9, 15, 9,
            271, 9, 143, 9, 399, 9, 79, 9, 335, 9,
            207, 9, 463, 9, 47, 9, 303, 9, 175, 9,
            431, 9, 111, 9, 367, 9, 239, 9, 495, 9,
            31, 9, 287, 9, 159, 9, 415, 9, 95, 9,
            351, 9, 223, 9, 479, 9, 63, 9, 319, 9,
            191, 9, 447, 9, 127, 9, 383, 9, 255, 9,
            511, 9, 0, 7, 64, 7, 32, 7, 96, 7,
            16, 7, 80, 7, 48, 7, 112, 7, 8, 7,
            72, 7, 40, 7, 104, 7, 24, 7, 88, 7,
            56, 7, 120, 7, 4, 7, 68, 7, 36, 7,
            100, 7, 20, 7, 84, 7, 52, 7, 116, 7,
            3, 8, 131, 8, 67, 8, 195, 8, 35, 8,
            163, 8, 99, 8, 227, 8
        };

        internal static readonly short[] static_dtree =
        {
            0, 5, 16, 5, 8, 5, 24, 5, 4, 5,
            20, 5, 12, 5, 28, 5, 2, 5, 18, 5,
            10, 5, 26, 5, 6, 5, 22, 5, 14, 5,
            30, 5, 1, 5, 17, 5, 9, 5, 25, 5,
            5, 5, 21, 5, 13, 5, 29, 5, 3, 5,
            19, 5, 11, 5, 27, 5, 7, 5, 23, 5
        };

        internal static StaticTree static_l_desc =
            new StaticTree(static_ltree, Tree.extra_lbits,
                LITERALS + 1, L_CODES, MAX_BITS);

        internal static StaticTree static_d_desc =
            new StaticTree(static_dtree, Tree.extra_dbits,
                0, D_CODES, MAX_BITS);

        internal static StaticTree static_bl_desc =
            new StaticTree(null, Tree.extra_blbits,
                0, BL_CODES, MAX_BL_BITS);

        internal short[] static_tree; // static tree or null
        internal int[] extra_bits; // extra bits for each code or null
        internal int extra_base; // base index for extra_bits
        internal int elems; // max number of elements in the tree
        internal int max_length; // max bit length for the codes

        StaticTree(
            short[] static_tree,
            int[] extra_bits,
            int extra_base,
            int elems,
            int max_length)
        {
            this.static_tree = static_tree;
            this.extra_bits = extra_bits;
            this.extra_base = extra_base;
            this.elems = elems;
            this.max_length = max_length;
        }
    }
}
